blkio: Some debugging aids for CFQ

o Some debugging aids for CFQ.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 18 insertions, 1 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 8bc31a50a57f..662d4e55b3c2 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -341,8 +341,21 @@ CFQ_CFQQ_FNS(coop);
 CFQ_CFQQ_FNS(deep);
 #undef CFQ_CFQQ_FNS
 
+#ifdef CONFIG_DEBUG_CFQ_IOSCHED
+#define cfq_log_cfqq(cfqd, cfqq, fmt, args...)  \
+        blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \
+                        cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \
+                        blkg_path(&(cfqq)->cfqg->blkg), ##args);
+
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)                          \
+        blk_add_trace_msg((cfqd)->queue, "%s " fmt,                     \
+                                blkg_path(&(cfqg)->blkg), ##args);      \
+
+#else
 #define cfq_log_cfqq(cfqd, cfqq, fmt, args...)  \
         blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args)
+#define cfq_log_cfqg(cfqd, cfqg, fmt, args...)          do {} while (0);
+#endif
 #define cfq_log(cfqd, fmt, args...)     \
         blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args)
 
@@ -832,6 +845,7 @@ cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg)
         if (cfqg->nr_cfqq)
                 return;
 
+        cfq_log_cfqg(cfqd, cfqg, "del_from_rr group");
         cfqg->on_st = false;
         cfqd->nr_groups--;
         st->total_weight -= cfqg->weight;
@@ -889,6 +903,9 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
                 cfqg->saved_serving_prio = cfqd->serving_prio;
         } else
                 cfqg->saved_workload_slice = 0;
+
+        cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime,
+                                        st->min_vdisktime);
 }
 
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
@@ -3102,7 +3119,7 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
         unsigned long now;
 
         now = jiffies;
-        cfq_log_cfqq(cfqd, cfqq, "complete");
+        cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", !!rq_noidle(rq));
 
         cfq_update_hw_tag(cfqd);